BÀI 2 TÍNH :
A = \(\dfrac{6^3+3.6^2+3^3}{13}\)
B = \(\dfrac{4^6.9^5+6^9.120}{8^4-3^{12}.6^{11}}\)
Câu 2: Tính
C = \(\dfrac{6^3+3.6^2+3^3}{13}\)
D = \(\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
\(C=\dfrac{6^3+3\cdot6^2+3^3}{13}=\dfrac{3^3\cdot8+3^3\cdot4+3^3}{13}=27\)
\(\dfrac{10^3+2.5^3+5^3}{55}-\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
\(=\dfrac{5^3\left(2^3+2+1\right)}{55}-\dfrac{2^{12}\cdot3^{10}+2^{12}\cdot3^{10}\cdot5}{2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}\)
\(=5^2-\dfrac{2^{12}\cdot3^{10}\cdot\left(1+5\right)}{2^{11}\cdot3^{11}\left(2\cdot3-1\right)}=25-\dfrac{2}{3}\cdot\dfrac{6}{5}\)
=25-4/5
=24,2
1. Thực hiện phép tính :
a) \(\dfrac{20^5.5^{10}}{100^5}\)
b) \(\dfrac{49^6,5-7^{11}}{\left(-7\right)^{10}.5-2.49^5}\)
c) \(\dfrac{6^3+3.6^2+3^3}{-13}\)
d) \(\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
e) A = \(1-\dfrac{1}{2}-\dfrac{1}{2^2}-\dfrac{1}{2^3}-...-\dfrac{1}{2^{10}}\)
2. Cho các biểu thức :
A = 3 + 32 + 33 + 34+... + 336
a) C/minh A chia hết cho 4
b) C/minh A chia hết cho 13
c) C/minh A chia hết cho 52
Bài 1:
\(a)\dfrac{20^5.5^{10}}{100^5}=\dfrac{20^5.5^5.5^5}{100^5}=\dfrac{100^5.3125}{100^5}=3125\)
2.
a)A có 36 sô hạng , chia A thành 18 nhóm , mỗi nhóm có 2 số hạng .
Ta có : A = \(\left(3+3^2\right)+\left(3^3+3^4\right)+....+\left(3^{35}+3^{36}\right)\)
\(A=3.\left(1+3\right)+3^3.\left(1+3\right)+...+3^{35}.\left(1+3\right)\)
\(A=3.4+3^3.4+...+3^{35}.4\)
\(A=4.\left(3+3^3+...+3^{35}\right)\)
Vậy A chia hết cho 4 .
b)Chia A thành 13 nhóm mỗi nhóm có 3 số hạng
Ta có : \(A=\left(3+3^2+3^3\right)+...+\left(3^{34}+3^{35}+3^{36}\right)\)
\(A=3.\left(1+3+9\right)+...+3^{34}.\left(1+3+9\right)\)
A=\(3.13+...+3^{34}.13\)
A= \(13.\left(3+..+3^{34}\right)\)
Vậy A chia hết cho 13
c) Tương tự như câu a và câu b
Bài 1:
b: \(=\dfrac{7^{12}\cdot5-7^{11}}{7^{10}\cdot5-2\cdot7^{10}}=\dfrac{7^{11}\cdot\left(7\cdot5-1\right)}{7^{10}\cdot3}=7\cdot\dfrac{34}{3}=\dfrac{238}{3}\)
c: \(=\dfrac{3^3\cdot2^3+3^3\cdot2^2+3^3}{-13}=\dfrac{3^3\cdot13}{-13}=-27\)
d: \(=\dfrac{2^{12}\cdot3^{10}+2^{12}\cdot3^{10}\cdot5}{2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}=\dfrac{2^{13}\cdot3^{11}}{2^{11}\cdot3^{11}\cdot5}=\dfrac{4}{5}\)
Thực hiện phép tính:
a. A=\(\dfrac{5^2.6^{11}.16^2+6^2.12^6.15^2}{2.6^{12}.10^4-81^2.960^3}\)
b. B=\(\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
a: \(A=\dfrac{5^2\cdot3^{11}\cdot2^{11}\cdot2^8+3^2\cdot2^2\cdot2^{12}\cdot3^6\cdot3^2\cdot5^2}{2\cdot2^{12}\cdot3^{12}\cdot2^4\cdot5^4-3^8\cdot960^3}\)
\(=\dfrac{5^2\cdot3^{11}\cdot2^{19}+3^{10}\cdot2^{14}\cdot5^2}{2^{17}\cdot3^{12}\cdot5^4-3^{11}\cdot2^{18}\cdot5^3}\)
\(=\dfrac{5^2\cdot2^{14}\cdot3^{10}\left(3\cdot2^5+1\right)}{2^{17}\cdot3^{11}\cdot5^3\left(3\cdot5-2\right)}=\dfrac{1}{5}\cdot\dfrac{1}{8}\cdot\dfrac{1}{10}\cdot\dfrac{97}{13}=\dfrac{97}{5200}\)
b: \(B=\dfrac{2^{12}\cdot3^{10}+2^9\cdot3^9\cdot2^3\cdot3\cdot5}{2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}\)
\(=\dfrac{2^{12}\cdot3^{10}\cdot\left(1+5\right)}{2^{11}\cdot3^{11}\left(2\cdot3-1\right)}=\dfrac{2}{3}\cdot\dfrac{6}{5}=\dfrac{12}{15}=\dfrac{4}{5}\)
rút gọn phân số
a)\(\dfrac{2727-101}{3.303+404}\) b)\(\dfrac{8.9-4.15}{12.7-180}\) c)\(\dfrac{-19}{3^2.7.11}\) d)\(\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
a) \(\dfrac{2727-101}{3.303+404}=\dfrac{2626}{909+404}=\dfrac{2626}{1313}=2\)
b) \(\dfrac{8.9-4.15}{12.7-180}=\dfrac{72-60}{84-180}=\dfrac{12}{-96}=\dfrac{-1}{8}\)
c) \(\dfrac{-19}{3^2.7.11}=\dfrac{-19}{9.7.11}=\dfrac{-19}{63.11}=\dfrac{-19}{693}\)
d) \(\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}=\dfrac{2^{12}.3^{10}+120.6^9}{2^{12}.3^{12}-6^{11}}=\dfrac{2^2.6^{10}+20.6.6^9}{6^{12}-6^{11}}=\dfrac{4.6^{10}+20.6^{10}}{6^{11}\left(6-1\right)}=\dfrac{\left(4+20\right).6^{10}}{5.6^{11}}=\dfrac{24}{30}=\dfrac{4}{5}\)
Giúp mk với nha ,plz!!! Mk tick cho !!!! <3
Tính giá trị biểu thức
E=\(\frac{4^6.9^5+6^9.120}{-8^4.3^{12}-6^{11}}\)
F=\(\frac{6^3+3.6^2+3^3}{-13}\)
E = \(\frac{\left(2^2\right)^6.\left(3^2\right) ^5+\left(2.3\right)^9.2^3.3.5}{-\left(2^3\right)^4.3^{12}-\left(2.3\right)^{11}}\)
E = \(\frac{2^{12}.3^{10}+2^9.3^9.2^3.3.5}{-2^{12}.3^{12}-2^{11}.3^{11}}\)
E = \(\frac{2^{12}.3^{10}+2^{13}.3^{10}.5}{-2^{11}.3^{11}.\left(2.3+1\right)}\)
E = \(\frac{2^{12}.3^{10}.\left(1+5\right)}{-2^{11}.3^{11}.7}\)
E = \(\frac{2^{12}.3^{10}.6}{-2^{11}.3^{11}.7}\)
E=\(\frac{-2^{11}.\left(-2\right).3^{10}.6}{-2^{11}.3^{10}.3.7}\)
E = \(\frac{-2.6}{3.7}=-\frac{4}{7}\)
Vậy E = -4/7
Ý F bn lm tương tự nha
tinh gia tri cua cac bieu thuc sau
\(\frac{20^{5.}5^{10}}{100^5}\)
b)\(\frac{6^3+3.6^2+3^3}{-13}\)
c)\(\frac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)l
a) 3125
b) -27
c) \(\frac{46}{5}\) hay 9,2
a) x4+x3+2x2+x+1=(x4+x3+x2)+(x2+x+1)=x2(x2+x+1)+(x2+x+1)=(x2+x+1)(x2+1)
b)a3+b3+c3-3abc=a3+3ab(a+b)+b3+c3 -(3ab(a+b)+3abc)=(a+b)3+c3-3ab(a+b+c)
=(a+b+c)((a+b)2-(a+b)c+c2)-3ab(a+b+c)=(a+b+c)(a2+2ab+b2-ac-ab+c2-3ab)=(a+b+c)(a2+b2+c2-ab-ac-bc)
c)Đặt x-y=a;y-z=b;z-x=c
a+b+c=x-y-z+z-x=o
đưa về như bài b
d)nhóm 2 hạng tử đầu lại và 2hangj tử sau lại để 2 hạng tử sau ở trong ngoặc sau đó áp dụng hằng đẳng thức dề tính sau đó dặt nhân tử chung
e)x2(y-z)+y2(z-x)+z2(x-y)=x2(y-z)-y2((y-z)+(x-y))+z2(x-y)
=x2(y-z)-y2(y-z)-y2(x-y)+z2(x-y)=(y-z)(x2-y2)-(x-y)(y2-z2)=(y-z)(x2-2y2+xy+xz+yz)
Tình hợp lý;:
a) \(\frac{6^3+3.6^2+3^3}{-13}\)
b) \(\frac{2^3+3.2^6-4^3}{2^3+3^2}\)
c) \(\frac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
d) \(\frac{5^5.20^3-5^4.20^3+5^7.4^5}{\left(20+5\right)^3.4^5}\)
plzz Helpppp:<<<
a)\(\frac{6^3+3\cdot6^2+3^3}{-13}=\frac{3^3\cdot2^3+3^3\cdot2^2+3^3}{-13}=\frac{3^3\left(2^3+2^2+1\right)}{-13}=-3^3=-27\)
b) \(\frac{2^3+3\cdot2^6-4^3}{2^3+3^2}=\frac{8+3\cdot64-64}{8+9}=\frac{8+192-64}{17}=\frac{136}{17}=8\)
c) \(\frac{4^6\cdot9^5+6^9\cdot120}{8^4\cdot3^{12}-6^{11}}=\frac{2^{12}\cdot3^{10}+2^9\cdot3^9\cdot2^3\cdot3\cdot5}{2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}=\frac{2^{11}\cdot3^{10}\left(2+2\cdot5\right)}{2^{11}\cdot3^{10}\cdot\left(2\cdot3^2-3\right)}=\frac{12}{18-3}=\frac{12}{15}\)
d) \(\frac{5^5\cdot20^3-5^4\cdot20^3+5^7\cdot4^5}{\left(20+5\right)^3\cdot4^5}=\frac{5^5\cdot20^3-5^4\cdot20^3+20^3\cdot20^2\cdot5^2}{5^6\cdot4^5}=\frac{20^3\left(5^5-5^4+5^4\cdot4^2\right)}{20^5\cdot5}\)\(=\frac{5^4\left(5-1+16\right)}{20^2\cdot5}=\frac{5^4\cdot20}{20^2\cdot5}=\frac{5^3}{20}=\frac{5^3}{5\cdot4}=\frac{25}{4}\)
Bài giải
a)\(\frac{6^3+3\cdot6^2+3^3}{-13}=\frac{3^3\cdot2^3+3^3\cdot2^2+3^3}{-13}=\frac{3^3\left(2^3+2^2+1\right)}{-13}=-3^3=-27\)
b) \(\frac{2^3+3\cdot2^6-4^3}{2^3+3^2}=\frac{8+3\cdot64-64}{8+9}=\frac{8+192-64}{17}=\frac{136}{17}=8\)
c) \(\frac{4^6\cdot9^5+6^9\cdot120}{8^4\cdot3^{12}-6^{11}}=\frac{2^{12}\cdot3^{10}+2^9\cdot3^9\cdot2^3\cdot3\cdot5}{2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}=\frac{2^{11}\cdot3^{10}\left(2+2\cdot5\right)}{2^{11}\cdot3^{10}\cdot\left(2\cdot3^2-3\right)}=\frac{12}{18-3}=\frac{12}{15}\)
d) \(\frac{5^5\cdot20^3-5^4\cdot20^3+5^7\cdot4^5}{\left(20+5\right)^3\cdot4^5}=\frac{5^5\cdot20^3-5^4\cdot20^3+20^3\cdot20^2\cdot5^2}{5^6\cdot4^5}=\frac{20^3\left(5^5-5^4+5^4\cdot4^2\right)}{20^5\cdot5}\)\(=\frac{5^4\left(5-1+16\right)}{20^2\cdot5}=\frac{5^4\cdot20}{20^2\cdot5}=\frac{5^3}{20}=\frac{5^3}{5\cdot4}=\frac{25}{4}\)
\(\dfrac{-4^6.9^5-6^9.120}{-8^4.3^{12}-6^{11}}\)
\(=\dfrac{-2^{12}\cdot3^{10}-2^{12}\cdot3^{10}\cdot5}{-2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}=\dfrac{2^{12}\cdot3^{10}\cdot6}{2^{11}\cdot3^{11}\cdot7}=\dfrac{2\cdot6}{3\cdot7}=\dfrac{12}{21}=\dfrac{4}{7}\)